[Plugin : GD Star Rating] gdsr.css.php empty when loaded

Hello

I have a great problem I’m unable to solve by myself. A Theme/CSS/Plugin one …
I use WordPress 3.3.1, with videozoom 2.6 and GD Star Rating 1.9.17

gamer-tube.fr login: test ; mdp: test123;

When I switch to other themes, no problem. But with this one, without any modification nor plugins, it won’t.
After long time searching, I discover that GD Star Rating CSS was generated by PHP (not static CSS).
When I check loaded stylesheets, I see that gdsr.css.php is empty with videozoom, but not with other.
As I said, It work with other, so this doesn’t come from GD Star Rating itself, but with the loading of gdsr.css.php.
I double-checked folders and files rights and they are 755 and 644, so no problem.

Can you help me with this ? I think somewhere in my theme files sould be a problem calling or loading this gdsr.css.php file.

Best and Kind regards